ELECTROLUMINESCENT DEVICE MADE OF ORGANIC MATERIAL

摘要

This invention concerns an electroluminescent device, the electroluminescence spectrum of which does not overlap with the absorption spectrum, which contains two or more organic layers between two electrodes. This device is characterized by the fact that a) two neighboring organic layers each have an optical band gap of at least 2.5 eV, and b) the wave length ( lambda max corresponding to an energy Emax), at which the electroluminescence reaches a maximum, lies in the range which corresponds to the energy difference DELTA E (ionization potential of the first organic layer minus electron affinity of the second organic layer), Emax being less than or equal to 2.5 eV.